The present disclosure relates to a power line communication system where a plurality of power line communication devices are connected to each other via a power line and can perform signal modulation/demodulation operation under a plurality of modulation/demodulation schemes, and a power line communication device constituting such a power line communication system.
In recent years, with the evolution and proliferation of networks, interest has been growing in power line communication (PLC) that is a communication technology using power lines. The range of application of this technology has spread, not only to networks in ordinary homes and ships, but also to fields such as automobiles.
In a power line communication system disclosed in Japanese Patent Publication No. 2004-201065 (Patent Document 1), a plurality of power line communication devices (electric appliances) are connected via a power line. In this power line communication system, when communication is performed between power line communication devices different in modulation/demodulation scheme, a management device converts a signal transmitted from one power line communication device to the other to a signal of a modulation/demodulation scheme adopted by the other power line communication device (receiver). The power line also supplies electric power received from a power company to the power line communication devices.
Japanese Patent Publication No. 2008-205678 (Patent Document 2) discloses a power line communication device that performs modulation operation of modulating an internal signal to be transmitted to a power line and demodulation operation of demodulating an external signal received from the power line. This power line communication device, which receives electric power via the power line, switches the mode of the modulation/demodulation operation to a power saving mode according to environmental temperature changes, etc.